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On Apr 19, 11:47�pm, AF6AY wrote:
xxx wrote on Thu, 19 Apr 2007 07:41:27 EDT: Due to time limitations, this post will comment on just one of Len's claims: * *1. *"Discovery of 'shortwaves' enabling worldwide communications: * * * Already known by non-hobbyist technologists. Which ones? And why weren't they *using* those shortwaves before amateurs led the way? *Radio amateurs * * * were forced upwards in frequency use by politics, not * * * pioneering. *It was fortuitous for amateurs, yes, but not * * * necessarily of their own and objected-to at the time by * * * amateurs. The conventional wisdom of the early professionals in radio was that the longer the wave, the farther it would go along the earth's surface. The shorter waves were considered useless, or at least unreliable, for long-distance communication, because ionospheric propagation was not known at the time. Long-distance non-amateur radio used waves thousands or tens of thousands of meters long for communications across oceans and beyond. This required enormous antennas and high power levels, all of which were developed for the purpose. The Alexanderson-alternator station SAQ, now a museum that operates a few times per year, is a prime example of the professional state of the art at the time. SAQ operates at 17.2 kHz After 1912, amateurs were required to use waves no longer than 200 meters. They were further restricted to 1000 watts input, which was very low power by professional long-distance-radio standards. Most anateurs stayed right at that wavelength, following the professionals' statements that shorter waves were less effective. Some amateurs and non-amateurs conducted experiments at shorter wavelengths but the results were not promising. The radio developments of World War 1 did not materially change the situation. In those days the "gold standard" of communication was whether the Atlantic Ocean could be crossed. Marconi's claim of transatlantic reception of the single letter "S" was considered a major accomplishment at the time. In December of 1921, the ARRL sent Paul Godley to the UK to listen for American amateurs on 200 meters. He heard several, and not just coastal stations. But two-way transatlantic communication eluded amateurs on 200 meters. In November of 1923, documented two-way transatlantic radio communication was achieved on approximately 110 meters by two American and one French amateur, using less than 1000 watts input. This success led to others, with transpacific and antipodal shortwave amateur communications following in short order. If the effectiveness of shortwave radio was known by nonamateurs, why didn't they use it until after amateurs pointed the way and proved it by their pioneering success? 73 de Jim, N2EY |
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